Enameling furnace conveyer



Aug. 18, 1931. R. MacDOUGALL ENAMELING FURNACE CONVEYER' 3 Sheets-Sheet1 Original Filed Sept. 10, 1928 Q 7zue7i/to 7753170 3 Sheets-Sheet 3 @WWm W10; N@ N@ how Km w F,

R. M DOUGALL ENAMELING FURNACE CONVEYER Original Filed Sept. 10, 1928Aug. 18, 1931.

Patented Aug. E 3931 STATES PATENT OFFICET ROBERT MAGDOUGALL, OF DOWNERSGROVE, ILLINOIS, ASSIGNOR TO BEEMACK FUR- NAGE COMPANY, OF CICERO,ILLINOIS, A CORPORATION OF ILLINOIS ENAMELING FURNACE GONVEYER Originalapplication filed September 10, 1928, Serial No. 304,945. Divided andthis application filed May 5, 1930. Serial No. 449,816.

My invention relates to improvements. in a furnace adapted particularlyfor drylng and fusing a coating of vitrifiable materials which has beenapplied in the form of a thin aqueous paste to sheet metal articles suchas kitchen utensils and similar articles, to produce an adherentvitrified enamel covering. This application is adivision of my copendingapplication No. 304,945, filed September The object of thepresent'invention is to provide an improved construction of the conveyerchain and carriers thereon employed for supporting articles passingthrough'the furnace.

In the accompanying drawings, I have illustrated, for purposes ofexposition and explanation art 0' an enameling furnace and associateapparatus in which my invention is embodied;

Fig. 1 is a transverse vertical section of a top portion of the furnaceillustrating the conveyer improvements;

Fig. 2 is a central section through Fig. 1;

Figs. 3 and 4 are transverse vertical seo-- tions of the dryingchambers;

Fig. 5 is a side view of a portion of the auxiliary furnace illustratedin Fig. 4;

Fig. 6 illustrates the carrier device employed for supporting articlesas they pass through the main furnace;

Fig. 7 is a view of the same as seen at right an les thereto;

ig. 8 is a plan view of the same; .Fig. 9 is a view of a modified formof carrier;

Figs. 10 and 11 are respectively a perspective and fragmentary sectionof a supporting pin used for supporting certain classes of articles inthe carrier devices illustrated in Figs. 6 to 9 inclusive; and

Fig. 12 is a detail showing a joint between certain bafliing members.

The furnace, as shown more fully in the earlier application'ref'erredto, consists of a central burning. or vitrifying section at the middleof the structure, with an extension or pro-heating section at each endthereof, preferably in alignment therewith, and additional. or dryingsections at the outer ends of the pro-heating sections also preferablyin alignment with the other sections.

The main furnace structure has two parallel slots through the roof fromone end to the other. An endless conveyer chain with depending partstravels through one of said slots in one direction returning as a loopoutside of the furnace. Another chain conveyer loop passes in theopposite direction through the other slot. Two auxiliary drying furnacesare provided, one on each side of the main furnace structure and each ofsaid chain con'veyer loopspasses through one of said auxiliarydryingfurnaces through a slot in the roof.

The carrier chains of my novel improved furnace are constructed in asimple and efiicient manner, with especial reference to protectionagainst undue heating of the links of the chain and the upper ends ofthe suspension rods by mealis of which the articles to be enameled aretransported through the burning chamber. The chains are eachconstructed,see Figs. 1 and 2of inner link members 16 and 16 bothconsisting of upper and lower plate sections connected by orificed hubsby means of which they are driven and are pivoted to intermediate pairsof outer. link members 17. The lower plate sections of the inner linkmembers 16 and 16 are formed with pivoting lugs to which are pivotallyconnected depending bafile plate members 34, which will later bereferred to again. i

The links 16 spaced at short intervals throughout the chain, are formedwith suspension brackets 18 which at their upper ends are severallyformed with hubs which pivotally support a pair of rollers 1919 runningupon tracks 2020 which are stationarily supported and extend between thesprocket wheels around which the two chains severally travel. Withinthevertical planes of the endsof the auxiliary furnacessee F1 s. 3, 4 and5the tracks may convenient ly %e secured within the sides of an invertedthree-sided hood 21, open at the bottom, extending down into the furnacechamber, and suspended from the under side of an I-beam 22 extendinglongitudinally above the center pairs being severally bolted to crossframe members 29 on each side of two narrow tapering slots, marked 30,slightly wider at the bottom than the top, which severally extend onopposite sides of the top of the furnace centrally through the burningchamber on the particular side and the aligned portions of thepreheating and drying sections of the furnace. Seated in the furnacewall at the upper end of each slot 30 are two opposite lines of bafflingrails 31, formed with lugs also connectedby bolts severally to thebracket plates 28. These baffling rails are preferably shouldered attheir meeting ends, to provide mating joints, offset at top andbottom,see Fig. 12. Between the bracket plates and the track members andbaffling rails are secured thin three-sided sheet metal hood members 32which make telescopic sealed connection with hood members 33, providingan airtight conduit into which cool air under a slight degree ofpressure is admitted at a point about midway between the ends of thefurnace. While the ends of the air conduit are open there is su'flicientpressure over the central part of the furnace, above the burning chamberand adjacent portions of the preheating chambers, to balance thetendency of the highly heated air within such chambers to rush upwardlythrough the slots 30.

The battling rails 31 have the cross-sectional form shown in Fig. 1,thus providing for a shouldered recess on each side of the slot 30 toreceive upper flange portions a of the baffle blocks 34 hereinbeforementioned. These blocks are also formed with lower flanges b whichextend between the sides of the slot below the plane of the bafflingrails, and the upper flanges are cut away at one end and extended at theother (see Fig. 2) so that in the assembled chain, rays of radiant heatfrom below are intercepted and direct passage of heated air through thegaps between the blocks is prevented. The blocks are also centrallyorificedand recessed to permit insertion into seats therein of thehooked upper ends of suspension rods 35 which carry the skeleton carrierboxes employed to contain and suspend the articles to be enameledthrough the various furnace chambers.

It is obvious, from the description of the chain assembly abovedescribed, that radiant heat from the burning chamber in which the heatis most intense), will largely be absorbed by the lower flanged portionof the baffle blocks 34, and taken up by the cool air slowly forced downand seeping from above through the tortuous passages between the bafflerails and baffle plates. In practice, it has been found that thesuspension rods 35 (which require frequent replacement) are not heatedabove redness for a distance of a foot or more from their upper ends,and the conveyor chain members are adequately protected from injurycaused by heat escaping through the slot in the top furnace wal Whilethe baflling blocks 34 are all arranged to engage suspension rods 35, inorder to provide for spacing the latter as may be desired, it is ingeneral found convenient to attach the rods to the blocks 16* whichcarry the roller supporting the chain, and to connect these rodsflexibly together by means of upper and lower spacing links, 50 and 50respectively, having overlapping looped ends engaging pivots 51 formedwith upper hooks arranged to engage hooks formed on the lower ends ofthe suspension rods and lower hooks arranged to engage the top crossmembers of the carrier boxes next to be described.

Describing first the form of box illustrated in Figs. 6 to 8,inclusive,'the ends of the box consist of a pair of frames having sidebars 52 (which may be made of metal tubing, flattened at top and bottom,as shown) secured to a top cross member 53, preferably formed with a rowof orifices for the engagement of suspension hooks, and to a bottomcross strip 54, which preferably extends beyond the side bars 52. A pairof such frames, suspended from chains by the hooked pivots 51, are tiedtogether by what I term a box tool, consisting of a frame having sidemembers 55-55, and cross members 5656. The side members 55 are notchedon both sides near their opposite ends (see Fig. 7), so that when warpedand bowed downwardly by the weight of articles carried in the box underthe extreme heat to which they are subjected in the burning chamber, thebox tools may be inverted, the notches in either position being arrangedto fit over the cross strip 54 of the carrier frames. Removable supportsfor the articles to be enameled, of the ordinary type illustrated inFigs. 7 and 8, may be placed on the box tools, as desired.

As indicated in Fig. 7, the spacing links between the carrier boxes arealso utilized for suspending articles to be treated, by means of hooksengaging such links and flanges on articles such as jars, or the like.which are formed with flanges capable of being engaged by such hooks.

The form of carrier'box illustrated in Fig. 9 differs from that abovedescribed in having end frames formed with longer side bars 57-57 whichare constructed with bonds providing seats for attachment of the ends ofintermediate cross-strips 58, and having a bottom cross-strip 54corresponding to the cross-strip 54 of the previously described form ofbox. The box tools above described may be engaged with either theintermediate cross-strips, or the bottom cross-strips of a pair ofadjacent frames of the last described construction.

- I have also illustrated in said Fig. 9, and Figs. 10 and 11 a form ofbox tool adapted to suport certain classes of articles, such as pans andother articles having a broad flat bottom. This tool consists of a flatstrip 59 having end bends adapted to hook over the cross-stri s of apair of frames, and formed with sockets arranged to loosely receivepointed flanged studs 60, which may be replaced as soon as they becomesmeared in use with the enameling composition. At appropriate workstations between the furnace, work tables are arranged adjacent to theline of travel of the conveyer chain.

What I claim is:

1. In apparatus of the class described and having a heating passage anda metal-link conveyer chain equipped with suspension rods extendingdownwardly into said pasbers and a horizontal bottom member extendingoutside the planes of said side members, and tool frames extendingacross spaces between the box frames and connected adjacent oppositeends to a pair of such box frames, said tool frames including memberslonger than the distance between said box frames and arranged tointerlock with said horizontal member of such box frame inside the planeof said vertical members, whereby lateral displacement is prevented.

In testimony whereof, I have subscribed my name.

ROBERT MAoDOUGALL.

sage, means for suspending articles through said rods including spacinlinks flexibly connecting the lower ends 0 the rods, transverselydisposed skeleton box frames also flexiblyconnected. to .said rods, andtool frames extending across spaces between the box frames and connectedadjacent opposite ends to a pair of such frames.

2. In apparatus .of the class described and having a heating passage anda metal-link conveyer chain equipped with suspension rods extendingdownwardly into said passage, means for suspending articles through saidrods including skeleton box-frames flexi'bly connected to said rods anddis osed transversely of the line of travel of the c ain, and toolframes extending across spaces between the box frames and connected atopposite ends to such flat metal'strips set edgewise and notched on oposite sides to reversibly engage a pair of sai box frames.

3. In apparatus of the class described having a heating chamber ofrefractory material with a slot through the top, alink conveyer,

havin suspension members pivotally connecte thereto and dependin throughsaid slot, means secured to said li s-for supporting articles to beenameled and a steel structure above said heating chamber and supportedat the side thereof independently of said refractory material forcarrying the weight of said link conveyer. a 4. In apparatus of theclass described an having a heating passage and a metal-link conveyerchain equipped with suspension rods extending downwardly into saidpassage,means for suspending articles through said rods includingskeleton box frames flexibly connected to said rods and disposedtransversely of the line of travel of the chain, said bo'x framesincluding vertical side mem-

